Definition of listener terms

The following terms are used when discussing Unica Campaign listeners and listener clustering.

Term Definition
Back-end The components and communication related to the Unica Campaign listener and its interactions with other back-end server processes.
Cluster A listener cluster is a set of two or more listeners that act as a unit to provide load balancing and high availability with minimal down-time. Clustered nodes provide continued service when system components fail. Unica Campaign listener clusters are Active-Active, meaning each node serves requests using a load-balanced approach.
Failover Automatically switching to an alternate node in a cluster.
Front-end The components and communication related to the Unica Campaign web application that provides the user interface.
High availability (HA) A continuously operational system or component.
Listener A server process that provides an interface to back-end analytical server processes. This interface is used by clients (such as the Unica Campaign web application and the Unica Campaign Server Manager) to connect to back-end servers. Each listener spawns processes to handle user and flowchart interactions. The listener is sometimes called the analytic server.
Load balancer A component of the Unica Campaign master listener whose purpose is to coordinate load balancing among clustered listener nodes.
Master listener The listener that controls the coordination of clustered nodes. Every cluster has one master listener. Any node in the cluster can act as the master listener. The master listener includes the load balancer component.
Node Each listener in a cluster. Any node in the cluster, including the master listener, can serve a request from the web application.
Load based routing A load balancing algorithm that distributes traffic proportionally to servers based on the user-specified ranking (weight) of each server.

Starting Campaign 12.0, there is no separate listener for Optimize, since it is integrated into Campaign listener.

Campaign Listener (unica_aclsnr) can handle not only flowchart execution, but also Optimize session execution, depending on the ListenerType parameter value. There are 3 ListenerType parameter values as follows.

"1" - This is CAMPAIGN_ONLY type of listener which is able to execute only flowcharts.

"2" - This is OPTIMIZE_ONLY type of listener which is able to execute only optimize sessions.

"3" - This is BOTH type of listener which is able to execute flowcharts as well as optimize sessions.